The present disclosure relates to an electrophotographic image forming apparatus including a developing device for supplying developer to an image carrier.
The electrophotographic image forming apparatus irradiates a cylindrical surface of the image carrier (a photosensitive drum) with light based on image information read from a document image or image information transmitted from an external device such as a computer so as to form an electrostatic latent image, supplies the electrostatic latent image with toner from the developing device so as to form a toner image, and then transfers the toner image onto a paper sheet. The paper sheet after the transfer process undergoes a fixing process of the toner image and then is discharged externally.
In recent years, along with progress of color printing and faster processing, structure of the image forming apparatus becomes complicated. In addition, in order to support faster processing, high speed rotation of a toner stirring member in the developing device is inevitable. In particular, in a developing method using two-component developer containing magnetic carrier and toner, a magnetic roller (toner supply roller) carrying developer, and a developing roller carrying only toner, in opposed position of the developing roller and the magnetic roller, only toner is carried by the developing roller with a magnetic brush formed on the magnetic roller, and further toner that was not used for developing is separated from the developing roller. Therefore, toner is apt to scatter in a vicinity of the opposed position of the developing roller and the magnetic roller, and toner floating in the developing device is deposited around periphery of the ear cutting blade (restricting blade). Then, the deposited toner coagulates and sticks to the developing roller, and hence toner drop occurs so that image malfunction may occur.
Therefore, for example, there is known a developing device using two-component developer containing magnetic carrier and toner, a magnetic roller for carrying developer, and a developing roller carrying only toner, in which the developing device includes a toner receiving support member facing the developing roller or the magnetic roller, a toner receiving member disposed along a longitudinal direction of the toner receiving support member so as to receive toner falling from the developing roller, and oscillation generation means for oscillating the toner receiving member.